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<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="fusion.support.deduce"></a><a class="link" href="deduce.html" title="deduce">deduce</a>
</h3></div></div></div>
<h5>
<a name="fusion.support.deduce.h0"></a>
        <span class="phrase"><a name="fusion.support.deduce.description"></a></span><a class="link" href="deduce.html#fusion.support.deduce.description">Description</a>
      </h5>
<p>
        Metafunction to apply <a class="link" href="../notes.html#fusion.notes.element_conversion"><span class="emphasis"><em>element
        conversion</em></span></a> to the full argument type.
      </p>
<p>
        It removes references to <code class="computeroutput"><span class="keyword">const</span></code>,
        references to array types are kept, even if the array is <code class="computeroutput"><span class="keyword">const</span></code>.
        Reference wrappers are removed (see <a class="link" href="../notes.html#fusion.notes.reference_wrappers"><code class="computeroutput"><span class="identifier">Reference</span> <span class="identifier">Wrappers</span></code></a>)<a href="#ftn.fusion.support.deduce.f0" class="footnote" name="fusion.support.deduce.f0"><sup class="footnote">[5]</sup></a>.
      </p>
<h5>
<a name="fusion.support.deduce.h1"></a>
        <span class="phrase"><a name="fusion.support.deduce.header"></a></span><a class="link" href="deduce.html#fusion.support.deduce.header">Header</a>
      </h5>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">support</span><span class="special">/</span><span class="identifier">deduce</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">deduce</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
</pre>
<h5>
<a name="fusion.support.deduce.h2"></a>
        <span class="phrase"><a name="fusion.support.deduce.synopsis"></a></span><a class="link" href="deduce.html#fusion.support.deduce.synopsis">Synopsis</a>
      </h5>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">traits</span>
<span class="special">{</span>
    <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">&gt;</span>
    <span class="keyword">struct</span> <span class="identifier">deduce</span>
    <span class="special">{</span>
        <span class="keyword">typedef</span> <span class="emphasis"><em>unspecified</em></span> <span class="identifier">type</span><span class="special">;</span>
    <span class="special">};</span>
<span class="special">}</span>
</pre>
<h5>
<a name="fusion.support.deduce.h3"></a>
        <span class="phrase"><a name="fusion.support.deduce.example"></a></span><a class="link" href="deduce.html#fusion.support.deduce.example">Example</a>
      </h5>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">holder</span>
<span class="special">{</span>
    <span class="keyword">typename</span> <span class="identifier">traits</span><span class="special">::</span><span class="identifier">deduce</span><span class="special">&lt;</span><span class="identifier">T</span> <span class="keyword">const</span> <span class="special">&amp;&gt;::</span><span class="identifier">type</span> <span class="identifier">element</span><span class="special">;</span>

    <span class="identifier">holder</span><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span> <span class="special">&amp;</span> <span class="identifier">a</span><span class="special">)</span>
      <span class="special">:</span> <span class="identifier">element</span><span class="special">(</span><span class="identifier">a</span><span class="special">)</span>
    <span class="special">{</span> <span class="special">}</span>
<span class="special">};</span>

<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">&gt;</span>
<span class="identifier">holder</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">make_holder</span><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span> <span class="special">&amp;</span> <span class="identifier">a</span><span class="special">)</span>
<span class="special">{</span>
    <span class="keyword">return</span> <span class="identifier">holder</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;(</span><span class="identifier">a</span><span class="special">);</span>
<span class="special">}</span>
</pre>
<h5>
<a name="fusion.support.deduce.h4"></a>
        <span class="phrase"><a name="fusion.support.deduce.see_also"></a></span><a class="link" href="deduce.html#fusion.support.deduce.see_also">See
        also</a>
      </h5>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
            <a class="link" href="deduce_sequence.html" title="deduce_sequence"><code class="computeroutput"><span class="identifier">deduce_sequence</span></code></a>
          </li></ul></div>
<div class="footnotes">
<br><hr style="width:100; text-align:left;margin-left: 0">
<div id="ftn.fusion.support.deduce.f0" class="footnote"><p><a href="#fusion.support.deduce.f0" class="para"><sup class="para">[5] </sup></a>
          Since C++11, the standard reference wrappers are also removed.
        </p></div>
</div>
</div>
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<td align="right"><div class="copyright-footer">Copyright © 2001-2006, 2011, 2012 Joel de Guzman,
      Dan Marsden, Tobias Schwinger<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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